212551421 has 16 divisors (see below), whose sum is σ = 225227520. Its totient is φ = 200315520.

The previous prime is 212551397. The next prime is 212551481. The reversal of 212551421 is 124155212.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-212551421 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212551481) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 252920 + ... + 253758.

It is an arithmetic number, because the mean of its divisors is an integer number (14076720).

Almost surely, 2^212551421 is an apocalyptic number.

It is an amenable number.

212551421 is a deficient number, since it is larger than the sum of its proper divisors (12676099).

212551421 is a wasteful number, since it uses less digits than its factorization.

212551421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1084.

The product of its digits is 800, while the sum is 23.

The square root of 212551421 is about 14579.1433561784. The cubic root of 212551421 is about 596.7897254929.

The spelling of 212551421 in words is "two hundred twelve million, five hundred fifty-one thousand, four hundred twenty-one".